1. Field of the Invention
The present invention relates to low level luminaries and more particularly to an imitation candle used primarily for ornamentation and establishing ambience.
2. Description of the Problem
Many people find candle light pleasant. The flickering of light and movement of shadows across a floor or on a nearby wall can be almost hypnotically soothing. As a result, candles have remained popular for generations since the invention of more practical electrical lighting, especially for decorative and mood setting purposes. This has remained so notwithstanding the hazard posed by open flames and the consequent danger of household fires. Few people consider it safe to leave a lit candle unattended.
Consequently, numerous manufacturers have attempted to meet a demand for a candle like luminary using electrical illumination. There are many imitation candles available that use incandescent lamps or LED""s as a light source. While these address people""s concern with the open flame, most try to implement the appearance of a realistic flame using a specially shaped bulb or lens that is exposed to view. Typically, the bulb or lens sits on top of a thin cylindrical sleeve, which is shaped and colored to resemble a candle. The results are typically disappointing, especially when these devices are not illuminated. The visible, flame shaped artificial light source makes the imitation candle as a whole appear artificial. The result can look more like a caricature of a candle than a real candle. The color of incandescent light can leave something to be desired in many candles as well.
The use of frosted glass cylinders around incandescent light sources to diffuse light is known. Such products are pleasant and popular. However, the light produced by an incandescent source can be quite broad, and the top of the lamp must be open to allow heat to escape. Another product, sold by Eternalight, Inc. of Cortaro, Ariz., provides a plurality of LEDs arranged on a base inside a frosted glass cylinder. A computer is used to control current supplied the LEDs to change the color and intensity of the light emitted to give an artificial flame shape and motion and to vary the intensity of the artificial flame. A similar product is sold by Norex Enterprises, Inc. of Blauvelt, N.Y. In both cases the products place the artificial flame above a base. A frosted glass cylinder, open at the top, is then set on the base. The appearance is intended to be of a candle inside a glass lamp.
Candles of course do not all come in one shape or size. While a classical image of a candle is of a long, thin, tapering rod, which stands upright in a candle stick and which leaves its flame exposed as it burns down, many candles come as a relatively short to circumference block or cylinder which is self supporting. Such candles commonly leave the outer wall of the candle intact as the candlewick burns down. When this happens, the candle flame is no longer visible when viewed from the side. This results in a diffuse, flickering glow visible through the paraffin wall of the candle.
One object of the invention is to provide an electrical candle that provides realistic candle like light.
Another object of the invention is to provide an electrical candle that presents a realistic appearance when the candle is not lit.
Yet another object of the invention is to provide an imitation candle that uses a light-sensing device to turn the light source off during the day.
Still another object of the invention is to provide a flicker circuit that provides three or more distinct light levels that vary in a pseudo-random manner to provide a realistic variation in light output akin to a candle flame being disturbed by gentle air currents. A realistic flicker provides one more subconscious cue that the candle is real.
Yet another object of the invention is to provide a luminary that gives a very realistic representation of a broad, self supporting candle that has burned down to the point where the flame is not visible.
These and other objects are achieved as is now described. The imitation candle of the present invention hides the light source within the body of the luminary which gives the body a glow in much the same way that a real wax candle glows when illuminated by a depressed flame. There is no shaped imitation flame to betray the fact that the candle is not real. The light source is preferably a light emitting diode enclosed within the translucent material forming the body of the luminary. The translucent material surrounds the light emitting diode on the sides and top at least to an extent necessary to make direct viewing of the light emitting diode inconvenient. The light emitting diode is positioned near the top of the body so that the top is brighter than the lower parts of the candlestick, which again simulates the appearance of a real candle. Placing the light emitting diode near the top also creates a hot spot of light that can be seen in the translucent material when viewed from above. Recessing the top within the side walls presents the appearance of a candle that has already been burning for some length of time. The body of the imitation candle can be made from real wax to further enhance the imitation candle""s realism. Alternatively, frosted glass or plastic materials may be used.
The invention provides an imitation candle having a body made from a translucent material having optically transmissive properties similar to candle paraffin. In a preferred embodiment the body of the imitation candle has a relatively large base or circumference relative to its height and is self supporting. The candle body is shaped to simulate a candle which has partially burned down, for example by forming a depression into an upper surface of a cylindrical candle body. A light emitting body, or similar small, high intensity light source, is set in a cavity enclosed within the translucent material. An emission color, such as amber, is selected for the LED to produce a light similar in color to candle light. The translucent material of the candle body diffuses the light emitted from the LED to create a warm, natural looking glow. When viewed from the side, the result is a very close approximation to a real candle when the wick has burned down to the point that the flame is not directly visible. The LED is preferably placed near the top of the translucent material but centered horizontally. The thinner material directly above the LED causes less diffusion of the light and produces a high intensity area of light that simulates the appearance of a candle flame when the candle is viewed from above.
The LED is preferably a super bright LED. Power consumption is low enough at low illumination levels that reasonable lifetimes can be achieved using batteries as a power source. Alternately, a wall-cube style power supply could be used to supply power and eliminate the need periodically to replace batteries. Alternately, rechargeable batteries can be used in conjunction with a solar cell or other recharging means. A simple circuit using multiple oscillators running at nearly the same frequency creates a realistic, pseudo-random flicker for light emitted by the LED. A simple light sensing device can be used to turn the LED off during daylight hours and extend battery life in battery operated versions of the candle.
Additional effects, features and advantages will be apparent in the written description that follows.